Add change_seq support

app/indexes/post_index.rb

@@ -15,6 +15,7 @@ module PostIndex
         indexes :score,             type: 'integer'
         indexes :fav_count,         type: 'integer'
         indexes :tag_count,         type: 'integer'
+        indexes :change_seq,        type: 'long'
 
         indexes :tag_count_general,   type: 'integer'
         indexes :tag_count_artist,    type: 'integer'
@@ -173,6 +174,7 @@ module PostIndex
       score:             score,
       fav_count:         fav_count,
       tag_count:         tag_count,
+      change_seq:        change_seq,
 
       tag_count_general:   tag_count_general,
       tag_count_artist:    tag_count_artist,

app/logical/elastic_post_query_builder.rb

@@ -159,6 +159,7 @@ class ElasticPostQueryBuilder
     add_range_relation(q[:score], :score, must)
     add_range_relation(q[:fav_count], :fav_count, must)
     add_range_relation(q[:filesize], :file_size, must)
+    add_range_relation(q[:change_seq], :change_seq, must)
     add_range_relation(q[:date], :created_at, must)
     add_range_relation(q[:age], :created_at, must)
 
@@ -442,6 +443,12 @@ class ElasticPostQueryBuilder
     when "id_desc"
       order.push({id: :desc})
 
+    when "change", "change_desc"
+      order.push({change_seq: :desc})
+
+    when "change_asc"
+      order.push({change_seq: :asc})
+
     when "md5"
       order.push({md5: :desc})
 

app/logical/post_query_builder.rb

@@ -138,6 +138,7 @@ class PostQueryBuilder
     relation = add_range_relation(q[:score], "posts.score", relation)
     relation = add_range_relation(q[:fav_count], "posts.fav_count", relation)
     relation = add_range_relation(q[:filesize], "posts.file_size", relation)
+    relation = add_range_relation(q[:change_seq], 'posts.change_seq', relation)
     relation = add_range_relation(q[:date], "posts.created_at", relation)
     relation = add_range_relation(q[:age], "posts.created_at", relation)
     TagCategory.categories.each do |category|
@@ -598,4 +599,4 @@ class PostQueryBuilder
 
     relation
   end
-end
+end

app/models/tag.rb

@@ -19,7 +19,7 @@ class Tag < ApplicationRecord
     -source id -id date age order limit -status status tagcount parent -parent
     child pixiv_id pixiv search upvote downvote voted filetype -filetype flagger
     -flagger appealer -appealer disapproval -disapproval set -set randseed -voted
-    -upvote -downvote description -description
+    -upvote -downvote description -description change
   ] + TagCategory.short_name_list.map {|x| "#{x}tags"} + COUNT_METATAGS + COUNT_METATAG_SYNONYMS
 
   SUBQUERY_METATAGS = %w[commenter comm noter noteupdater artcomm flagger -flagger appealer -appealer]
@@ -38,6 +38,7 @@ class Tag < ApplicationRecord
     portrait landscape
     filesize filesize_asc
     tagcount tagcount_asc
+    change change_desc change_asc
     rank
     random
     custom
@@ -686,6 +687,9 @@ class Tag < ApplicationRecord
           when "filesize"
             q[:filesize] = parse_helper_fudged(g2, :filesize)
 
+          when "change"
+            q[:change_seq] = parse_helper(g2)
+
           when "source"
             src = g2.gsub(/\A"(.*)"\Z/, '\1')
             q[:source] = (src.to_escaped_for_sql_like + "%").gsub(/%+/, '%')

db/migrate/20190815131908_add_change_seq.rb

@@ -0,0 +1,31 @@
+class AddChangeSeq < ActiveRecord::Migration[5.2]
+  def up
+    execute "set statement_timeout = 0"
+    add_column :posts, :change_seq, :bigserial, null: false
+    add_index :posts, :change_seq, unique: true
+    fields = %w[tag_string parent_id source approver_id rating description md5 is_deleted is_pending is_flagged is_rating_locked]
+    fields += %w[is_status_locked is_note_locked bit_flags has_active_children last_noted_at]
+    conditional = fields.map {|field| "NEW.#{field} != OLD.#{field}"}.join(' OR ')
+    execute <<SQL
+CREATE OR REPLACE FUNCTION posts_trigger_change_seq()
+  RETURNS trigger AS
+$BODY$
+BEGIN
+  IF #{conditional}
+  THEN
+     NEW.change_seq = nextval('public.posts_change_seq_seq');
+  END IF;
+  RETURN NEW;
+END;
+$BODY$ LANGUAGE 'plpgsql';
+SQL
+    execute "CREATE TRIGGER posts_update_change_seq BEFORE UPDATE ON posts FOR EACH ROW EXECUTE PROCEDURE posts_trigger_change_seq()"
+  end
+
+  def down
+    execute "set statement_timeout = 0"
+    execute "drop trigger posts_update_change_seq ON posts"
+    remove_column :posts, :change_seq
+    execute "drop function posts_trigger_change_seq"
+  end
+end

db/structure.sql

@@ -36,6 +36,23 @@ CREATE EXTENSION IF NOT EXISTS pg_trgm WITH SCHEMA public;
 COMMENT ON EXTENSION pg_trgm IS 'text similarity measurement and index searching based on trigrams';
 
 
+--
+-- Name: posts_trigger_change_seq(); Type: FUNCTION; Schema: public; Owner: -
+--
+
+CREATE FUNCTION public.posts_trigger_change_seq() RETURNS trigger
+    LANGUAGE plpgsql
+    AS $$
+BEGIN
+  IF NEW.tag_string != OLD.tag_string OR NEW.parent_id != OLD.parent_id OR NEW.source != OLD.source OR NEW.approver_id != OLD.approver_id OR NEW.rating != OLD.rating OR NEW.description != OLD.description OR NEW.md5 != OLD.md5 OR NEW.is_deleted != OLD.is_deleted OR NEW.is_pending != OLD.is_pending OR NEW.is_flagged != OLD.is_flagged OR NEW.is_rating_locked != OLD.is_rating_locked OR NEW.is_status_locked != OLD.is_status_locked OR NEW.is_note_locked != OLD.is_note_locked OR NEW.bit_flags != OLD.bit_flags OR NEW.has_active_children != OLD.has_active_children OR NEW.last_noted_at != OLD.last_noted_at
+  THEN
+     NEW.change_seq = nextval('public.posts_change_seq_seq');
+  END IF;
+  RETURN NEW;
+END;
+$$;
+
+
 --
 -- Name: sourcepattern(text); Type: FUNCTION; Schema: public; Owner: -
 --
@@ -1967,10 +1984,30 @@ CREATE TABLE public.posts (
     tag_count_species integer DEFAULT 0 NOT NULL,
     tag_count_invalid integer DEFAULT 0 NOT NULL,
     description text DEFAULT ''::text NOT NULL,
-    comment_count integer DEFAULT 0 NOT NULL
+    comment_count integer DEFAULT 0 NOT NULL,
+    change_seq bigint NOT NULL
 );
 
 
+--
+-- Name: posts_change_seq_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+CREATE SEQUENCE public.posts_change_seq_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: posts_change_seq_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: -
+--
+
+ALTER SEQUENCE public.posts_change_seq_seq OWNED BY public.posts.change_seq;
+
+
 --
 -- Name: posts_id_seq; Type: SEQUENCE; Schema: public; Owner: -
 --
@@ -3089,6 +3126,13 @@ ALTER TABLE ONLY public.post_votes ALTER COLUMN id SET DEFAULT nextval('public.p
 ALTER TABLE ONLY public.posts ALTER COLUMN id SET DEFAULT nextval('public.posts_id_seq'::regclass);
 
 
+--
+-- Name: posts change_seq; Type: DEFAULT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.posts ALTER COLUMN change_seq SET DEFAULT nextval('public.posts_change_seq_seq'::regclass);
+
+
 --
 -- Name: saved_searches id; Type: DEFAULT; Schema: public; Owner: -
 --
@@ -4482,6 +4526,13 @@ CREATE INDEX index_post_versions_on_updater_ip_addr ON public.post_versions USIN
 CREATE UNIQUE INDEX index_post_votes_on_user_id_and_post_id ON public.post_votes USING btree (user_id, post_id);
 
 
+--
+-- Name: index_posts_on_change_seq; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE UNIQUE INDEX index_posts_on_change_seq ON public.posts USING btree (change_seq);
+
+
 --
 -- Name: index_posts_on_created_at; Type: INDEX; Schema: public; Owner: -
 --
@@ -4902,6 +4953,13 @@ CREATE INDEX index_wiki_pages_on_title_pattern ON public.wiki_pages USING btree
 CREATE INDEX index_wiki_pages_on_updated_at ON public.wiki_pages USING btree (updated_at);
 
 
+--
+-- Name: posts posts_update_change_seq; Type: TRIGGER; Schema: public; Owner: -
+--
+
+CREATE TRIGGER posts_update_change_seq BEFORE UPDATE ON public.posts FOR EACH ROW EXECUTE PROCEDURE public.posts_trigger_change_seq();
+
+
 --
 -- Name: blips trigger_blips_on_update; Type: TRIGGER; Schema: public; Owner: -
 --
@@ -5187,6 +5245,7 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20190718201354'),
 ('20190801210547'),
 ('20190804010156'),
-('20190810064211');
+('20190810064211'),
+('20190815131908');